The IPHONE is 100% Compatible with ALL MB Bluetooth products.
In ALL cars that you have to purchase the Bluetooth adapter, everything transfers over.. PHonebook, etc.
I am a Mercedes-Benz Sales rep in San Diego, CA, and also use the Bluetooth adapter in both my cars successfully.
There are TWO ways to pair the device on the new C Class, 2009 SLK, 2009 SL, and the 2009 SUVS (all integrated Bluetooth)
On the E Class, S Class, CLS, and CLK Class, the "puck" is needed..
FOR IPHONE USERS: DO NOT BUY THE OLD VERSION, you need to latest version.
You can contact me shoudl you have questions